Energy Expenditure Estimation During Sedentary, Light, And Moderate Activity

Abstract

PURPOSE: Examine the validity of the Actical (AC) and ActiGraph wGT3X-BT (AG) accelerometers in estimating energy expenditure (EE) in METs during sedentary, light, and moderate activities. The study also wanted to examine if activity monitor placement impacted EE outcomes. METHODS: Twenty-two participants aged 20.4±1.7 years participated in the study. All participants completed 9 tasks (3 in each activity category) for a duration of four minutes. Participants simultaneously wore a portable indirect calorimetry device and both accelerometer models placed at five locations on the body: left and right wrist, left and right hip, and the right ankle. A counterbalanced design was used to minimize potential “order” effect. The manufacture’s 1-regression EE equation was used for all AC placements. The Swartz (2000) EE algorithm was used for all AG placements. One-way repeated-measures ANOVAs were used to examine differences between estimated EE by accelerometer model/placement and tasks compared to EE measured by indirect calorimetry. RESULTS: No significant differences in EE estimation were observed for sedentary activities (readings, standing still, laying) for both types of accelerometers, regardless of placement. During light activities, AG EE estimation was significantly different for treadmill walking (TM) at .894 m·s-1 at both hip, ankle, and right wrist placements (p values ≤ .02). AC EE estimation was significantly different for TM at .894 m·s-1 at both hip and ankle placements (p values ≤ .02). AC EE was also significantly different for arts and crafts at both wrist and hip placements (p values ≤ .04). During moderate activities, significant differences in EE estimation were observed for the AG during TM walking at 1.57 m·s-1 at the ankle placement (p < .001); stair climbing/descending at both wrist and ankle placements (p values ≤ .04); vacuuming at the right hip placement (p < .001). AC EE estimation significant differences included TM at 1.57 m·s-1 at both hip and ankle placements (p values ≤ .04); stair climbing/descending at both wrist and hip placements (p values = .03); vacuuming at the left wrist placement (p = 01). CONCLUSIONS: Accelerometer model and monitor placement impact EE estimates during sedentary, light, and moderate activities.